It is the abbreviated form of Enzyme-linked immunosorbent assay or EIA. It is similar in principle to Radio immune assay (RIA) but instead of radioactive substance it uses an enzyme. Chromogenic substrate is generated by reacting an enzyme conjugated with the antibody and a colorless substrate. Chromogenic substrate is a colored reaction product. Various enzymes … Read more
Immunoglobulin molecules themselves function as potent immunogens when they are introduced into other animal species to induce an antibody response. For studying the B cell development and humoral immune response, such anti-Ig antibodies are considered to be a powerful tool. The antigenic determinants are also called epitopes on immunoglobulin molecules. They are categorized into three … Read more
These are thin short filamentous appendages which measure about 1-1.5 micron in length and less than 4 to 8 nm in width. They extrude from the cytoplasmic membrane and are also called pili. They are found in certain gram-negative bacilli, including saprophytic, intestinal commensals, and pathogenic species in the family These are different kind from … Read more
The bite of rabid animal is the usual portal of entry which contains the infected saliva that is introduced into the depths of the wound. The virus may gain access through a pre-existing scratch or abrasion occasionally if this has been contaminated with the saliva. The virus multiplies locally in the tissues, invades adjacent nerve fibers, … Read more
Immunoglobulins are specialized serum proteins which are produced in response to an antigen and react with that antigen specifically. It may also react with the very closely related antigen as well. They are found in various secretions of body and some are fixed to body cells or tissues in addition to humoral antibodies. They are … Read more
Sterilization means the freeing of an article from all living forms that includes viruses, bacteria and their spores, fungi and their spores, both pathogenic and non-pathogenic forms. There are four different methods of sterilization. They are a) Heat b) Filtration c) Irradiation d) Chemical disinfection. The most widely applicable and reliable method is sterilization by … Read more
Introduction Some species of bacteria particularly those of Bacillus and Clostridium, develop structures called endospores. ‘Endo’ as prefix means within and endospores are highly differentiated cells which are able to tolerate harsh environment of heat, chemicals and radiations. They are highly resistant resting phase which can survive in a dormant state through a long period … Read more
Introduction Strains of bacteria which are motile possess filamentous, cytoplasmic appendages protruding through cell wall called flagella. This effect screw like propulsive movements and act as organs of locomotion. They are much thinner than the flagella or cilia of eukaryotes. The flagellum is a long, thin filament, hair-like, un-branched, twisted spirally in an open, regular … Read more
Nutritional environment regulates the bacterial growth. When a bacterium inoculated in a suitable liquid medium is incubated, its growth leads to an increase in the number of bacterial cells which follows a definite course. When bacterial count of such culture is determined periodically and plotted, a curve is obtained i.e. called growth curve. The growth … Read more
Introduction to Lymphoid Organs Lymphocytes, which are immature and generated in hematopoiesis gets mature and become committed to a particular antigenic specificity within the primary lymphoid organs. The cell becomes immune-competent only after the lymphocytes have matured in the primary lymphoid organs. T cells arise in the bone marrow and develop in the thymus. In … Read more